Questions tagged [units]
A specified amount of a quantity (e.g. voltage, current, power, time, etc.) by comparison with which any other quantity of the same kind is measured or estimated. The standard system of units is the International System of Units (SI).
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Inductance Computed As Length in Historical Document
In "Formulas and Tables for the Calculation of Mutual and Self-inductance.", many equations compute the inductance of an arrangement as a length. For example, Equation 95, on p. 150, states,...
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18650 cell will use ______ amps every _____mins?
I am looking at how to utilise the BQ77915 Ultra-Low Power Primary Protector with Autonomous Cell Balancing by TI, using eight 18650 cells, each with a BQ77915 IC allowing 3 series - 5 series cells.
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Time Domain Normalization of the IMP23ABSU Microphone
I have tried to evaluate the analog microphone (IMP23ABSU) built into the STEVAL-STWINKT1B with the FP-SNS-DATALOG1 (HS-Datalogger). The values were exported as "raw values" (this is an ...
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What does the "proportional symbol" (∝) mean when used as a time unit prefix?
In several datasheets for electronic components, I have seen a ∝ symbol used as a prefix for a time unit, usually seconds, writing as ∝s. As far as I know ∝ is not a valid SI prefix, so what does it ...
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I know the concept of per unit, but I don't know why am i wrong
A generator which apparent power is \$120MVA\$,and voltage is \$19.5kV,X_s=1.5p.u.\$. Now it is connected a transformer then connected to a transmission line. The rated value transformer is \$150MVA,...
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Meaning of long term stability unit (µV/mo)
What does 'mo' stand for in a long term stability spec which has units of μV/mo?
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In AC circuits, angles and frequency are measured in radians rather than degrees. Why?
Why do we use radians instead of degrees when working with alternators and the like? The maximum induced EMF in an alternator will be a completely different value if one calculated ω in degrees per ...
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Why is apparent power not measured in watts?
I'm studying circuit analysis. We are currently learning about AC circuits, particularly how power is calculated.
I learned that there are four types of power: Complex, apparent, active and reactive, ...
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What is the meaning of "a" and "z" in capacitor value - Cadence Virtuoso
What is the meaning of "a" and "z" in capacitor value? Here is the image:
I think "a" is angstrom, But I am not sure about it.
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Is "p" ever used to abbreviate pi in formulas?
I keep running into formulas in datasheets and articles that appear to be abbreviating pi as 'p'. An example from Ask The Applications Engineer-25: Op Amps Driving Capacitive Loads shows "1/2p...&...
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Comparing scattering parameters in dB and magnitude+angle forms
We're trying to compare the scattering parameters from two parts (ADG902 and BF1101). Their datasheets use dB and mag/angle respectively.
ADG902:
BF1101:
When trying to convert between the two, we ...
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Confused about MW to MWh conversion
I have various datasets of energy production in MW.
I need to present everything in MWh. I need to know if my data is already by the hour (logging a value for each hour of each day of an entire year), ...
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Battery capacity in mWh instead of mAh [duplicate]
I know that the capacity of a battery is expressed in mAh, i.e. A/s (international system of units). Today I used a command in PowerShell (*) in order to get the battery capacity, but the unit of ...
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Why are we able to ignore the henries, Hz, farads, siemens and ohms when calculating the characteristic impedance of a transmission line? [closed]
I have seen calculations, and every time we just take the coefficents of these values and end up calculating a simple complex number. The units all equate to various exponents of area, second, metre ...
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Schematics Standard for Space between Value and Unit
On electrical schematics, is there a standard for whether there is a space between the numerical value and unit symbol? I can find standards that require it in general writing, but none that ...
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